; ; Copyright 2007, Dengg David, david-d@gmx.at. All rights reserved. ; Copyright 2008, Michael Pfeiffer, laplace@users.sourceforge.net. All rights reserved. ; Copyright 2005, Ingo Weinhold, bonefish@users.sf.net. ; Copyright 2011, Axel Dörfler, axeld@pinc-software.de. ; Distributed under the terms of the MIT License. %assign USE_TEST_MENU 0 %assign BOOT_BLOCK_START_ADDRESS 0x7c00 %assign MBR_SIGNATURE 0xAA55 ; BIOS calls %assign BIOS_VIDEO_SERVICES 0x10 %assign BIOS_DISK_SERVICES 0x13 %assign BIOS_KEYBOARD_SERVICES 0x16 %assign BIOS_REBOOT 0x19 ; dl - boot drive number %assign BIOS_TIME_SERVICES 0x1A ; video services %assign SET_VIDEO_MODE 0x00 ; al - mode %assign SET_CURSOR_SHAPE 0x01 ; ch - starting scan line (5 bits) ; cl - ending scan line (5 bits) %assign SET_CURSOR 0x02 ; dl - column ; dh - row ; bh - page %assign GET_CURSOR 0x03 ; bh - page ; -> dl - column ; dh - row ; Cursor shape: ; ch - starting scan line ; cl - ending scan line %assign SCROLL_UP 0x06 ; al - lines (0: clear screen) ; bh - attribute ; ch - upper line ; cl - left column ; dh - lower line ; dl - right column %assign WRITE_CHAR 0x09 ; al - char ; bh - page ; bl - attribute ; cx - count ;%assign WRITE_CHAR 0x0e ; al - char ; bh - page ; bl - foreground color (graphics mode only) ; disk services %assign READ_DISK_SECTORS 0x02 ; dl - drive ; es:bx - buffer ; dh - head (0 - 15) ; ch - track 7:0 (0 - 1023) ; cl - track 9:8, ; sector (1 - 17) ; al - sector count ; -> al - sectors read %assign READ_DRIVE_PARAMETERS 0x08 ; dl - drive ; -> cl - max cylinder 9:8 ; - sectors per track ; ch - max cylinder 7:0 ; dh - max head ; dl - number of drives (?) %assign CHECK_DISK_EXTENSIONS_PRESENT 0x41 ; bx - 0x55aa ; dl - drive ; -> success: carry clear ; ah - extension version ; bx - 0xaa55 ; cx - support bit mask ; -> error: carry set %assign EXTENDED_READ 0x42 ; dl - drive ; ds:si - address packet ; -> success: carry clear ; -> error: carry set %assign FIXED_DISK_SUPPORT 0x1 ; flag indicating fixed disk ; extension command subset ; keyboard services %assign READ_CHAR 0x00 ; -> al - ASCII char ; ah - scan code %assign PROBE_CHAR 0x01 ; -> zf = 0 ; al - ASCII char ; ah - scan code %assign GET_MODIFIER_KEYS 0x02 ;-> al - modifier key bitmask ; timer services %assign READ_CLOCK 0x00 ; -> cx - high word ; dx - low word ; one tick = 1/18.2s %assign TICKS_PER_SECOND 19 ; video modes %assign GRAPHIC_MODE_80x25 0x12 ; 640 x 480 graphic mode %assign TEXT_COLUMNS 80 ; Number of columns %assign TEXT_ROWS 25 ; Number of rows ; Colors %assign BLACK 0 %assign BLUE 1 %assign GREEN 2 %assign CYAN 3 %assign RED 4 %assign MAGENTA 5 %assign BROWN 6 %assign LIGHT_GRAY 7 %assign DARK_GRAY 8 %assign LIGHT_BLUE 9 %assign LIGHT_GREEN 10 %assign LIGHT_CYAN 11 %assign LIGHT_RED 12 %assign LIGHT_MAGENTA 13 %assign YELLOW 14 %assign WHITE 15 %assign BRIGHT_COLOR_MASK 8 ; Characters %assign TRIANGLE_TO_RIGHT 16 %assign TRIANGLE_TO_LEFT 17 ; Key codes %assign KEY_DOWN 0x50 %assign KEY_UP 0x48 %assign KEY_PAGE_DOWN 0x51 %assign KEY_PAGE_UP 0x49 %assign KEY_HOME 0x47 %assign KEY_END 0x4f %assign KEY_RETURN 0x1C ; Modifier key bitmasks %assign MODIFIER_RIGHT_SHIFT_KEY 0x01 %assign MODIFIER_LEFT_SHIFT_KEY 0x02 %assign MODIFIER_CONTROL_KEY 0x04 %assign MODIFIER_ALT_KEY 0x08 %assign MODIFIER_SCROLL_LOCK_KEY 0x10 %assign MODIFIER_NUM_LOCK_KEY 0x20 %assign MODIFIER_CAPS_LOCK_KEY 0x40 %assign MODIFIER_INSERT_KEY 0x80 ; String constants with their length %define TITLE 'Haiku Boot Manager' %strlen TITLE_LENGTH TITLE %define SELECT_OS_MESSAGE 'Select an OS from the menu' %strlen SELECT_OS_MESSAGE_LENGTH SELECT_OS_MESSAGE ; 16 bit code SECTION .text BITS 16 ; nicer way to get the size of a structure %define sizeof(s) s %+ _size ; using a structure in a another structure definition %macro nstruc 1-2 1 resb sizeof(%1) * %2 %endmacro ; Variables on stack struc Locals selection resw 1 firstLine resb 2 ; low byte used only timeoutTicks resd 1 cursorX resb 1 cursorY resb 1 cursorShape resw 1 biosDrive resb 1 endstruc cursorPosition equ cursorX %macro DEBUG_PAUSE 0 push ax mov ah, READ_CHAR int BIOS_KEYBOARD_SERVICES pop ax %endmacro %macro CLEAR_SCREEN 0 mov ah, SCROLL_UP xor al, al mov bh, WHITE xor cx, cx mov dx, (TEXT_ROWS-1) * 0x100 + (TEXT_COLUMNS-1) int BIOS_VIDEO_SERVICES %endmacro ; Prints a null terminated string ; bl ... color ; si ... offset to string %macro PRINT_STRING 0 push ax push bx push cx push dx xor bh, bh ; write on page 0 jmp .loop_condition .loop: mov dx, [bp + cursorPosition] mov ah, SET_CURSOR int BIOS_VIDEO_SERVICES inc byte [bp + cursorX] mov cx, 1 mov ah, WRITE_CHAR int BIOS_VIDEO_SERVICES .loop_condition: lodsb cmp al, 0 jnz .loop pop dx pop cx pop bx pop ax ret %endmacro ; 64 bit value struc quadword .lower resd 1 .upper resd 1 endstruc ; address packet as required by the EXTENDED_READ BIOS call struc AddressPacket .packet_size resb 1 .reserved1 resb 1 .block_count resb 1 .reserved2 resb 1 .buffer resd 1 .offset nstruc quadword endstruc struc BootLoaderAddress .device resb 1 ; hard drive number .offset nstruc quadword ; LBA of start start sector endstruc ; use code available in stage 1 %define printstr printStringStage1 stage1: mov ax, 0x07c0 ; BOOT_BLOCK_START_ADDRESS / 16 mov ds, ax ; Setup segment registers mov es, ax mov ss, ax mov sp, 0xFFFF - sizeof(Locals) ; Make stack empty mov bp, sp mov [bp + biosDrive], dl ; Store boot drive cld ; String operations increment index ; registers CLEAR_SCREEN call hideCursor mov bh, 0 ; Text output on page 0 ; Print title centered at row 2 mov dx, 1 * 0x100 + (40 - TITLE_LENGTH / 2) mov [bp + cursorPosition], dx mov si, kTitle mov bl, WHITE call printstr ; Print message centered at second last row mov dx, (TEXT_ROWS-2) * 0x100 + (40 - SELECT_OS_MESSAGE_LENGTH / 2) mov [bp + cursorPosition], dx mov bl, LIGHT_GRAY mov si, kSelectOSMessage call printstr ; Chain load rest of boot loader mov ah, EXTENDED_READ ; Load 3 more sectors mov dl, [bp + biosDrive] mov si, nextStageDAP int BIOS_DISK_SERVICES jc .error ; I/O error jmp stage2 ; Continue in loaded stage 2 .error: call showCursor mov si, kError mov bl, RED call printstr mov ah, READ_CHAR int BIOS_KEYBOARD_SERVICES mov dl, [bp + biosDrive] int BIOS_REBOOT printStringStage1: PRINT_STRING hideCursor: mov ah, GET_CURSOR int BIOS_VIDEO_SERVICES mov [bp + cursorShape], cx mov ah, SET_CURSOR_SHAPE mov cx, 0x2000 int BIOS_VIDEO_SERVICES ret showCursor: mov cx, [bp + cursorShape] mov ah, SET_CURSOR_SHAPE int BIOS_VIDEO_SERVICES ret nextStageDAP: istruc AddressPacket at AddressPacket.packet_size, db 0x10 at AddressPacket.block_count, db 0x03 at AddressPacket.buffer, dw 0x0200, 0x07c0 at AddressPacket.offset, dw 1 iend kTitle: db TITLE, 0x00 kSelectOSMessage: db SELECT_OS_MESSAGE, 0x00 kError: db 'Error loading sectors!', 0x00 kStage1UnusedSpace equ 440 - ($-$$) ; Fill the missing space to reach byte 440 times kStage1UnusedSpace db 'B' kDiskSignature: dw 0, 0 kReserved: dw 0 kPartitionTable: times 64 db 0 kMBRSignature: ; Magic marker "AA55" (to identify a valid boot record) dw MBR_SIGNATURE ; ====================================================================== ; ======================= SECOND SECTOR ================================ ; ====================================================================== ; Use code available in stage 2 %define printstr printStringStage2 %assign TIMEOUT_OFF 0xffff stage2: mov ax, [defaultItem] ; Select default item mov [bp + selection], ax mov ax, TICKS_PER_SECOND ; Calculate timeout ticks mul word [timeout] mov bx, dx push ax mov ah, READ_CLOCK int BIOS_TIME_SERVICES pop ax ; Add current ticks add ax, dx adc bx, cx mov [bp + timeoutTicks], ax mov [bp + timeoutTicks + 2], bx mov al, [listItemCount] ; Calculate start row for menu shr al, 1 mov bl, TEXT_ROWS / 2 sub bl, al ; y = TEXT_ROWS / 2 - number of items / 2 mov [bp + firstLine], bl mov ah, GET_MODIFIER_KEYS ; Disable timeout if ALT key is pressed int BIOS_KEYBOARD_SERVICES and al, MODIFIER_ALT_KEY jz showMenu mov word [timeout], TIMEOUT_OFF showMenu: call printMenu cmp word [timeout], TIMEOUT_OFF je inputLoop timeoutLoop: mov ah, PROBE_CHAR int BIOS_KEYBOARD_SERVICES jnz inputLoop ; cancel timeout if key is pressed call isTimeoutReached jnc timeoutLoop jmp bootSelectedPartition isTimeoutReached: mov ah, READ_CLOCK int BIOS_TIME_SERVICES cmp cx, [bp + timeoutTicks + 2] jb .returnFalse ja .returnTrue cmp dx, [bp + timeoutTicks] ja .returnTrue .returnFalse: clc ret .returnTrue: stc ret ; ================== Wait for a key and do something with it ================== mainLoop: call printMenu inputLoop: mov ah, READ_CHAR int BIOS_KEYBOARD_SERVICES ; AL = ASCII Code, AH = Scancode cmp ah, KEY_DOWN je selectNextPartition cmp ah, KEY_PAGE_DOWN je selectLastPartition cmp ah, KEY_END je selectLastPartition cmp ah, KEY_UP je selectPreviousPartition cmp ah, KEY_PAGE_UP je selectFirstPartition cmp ah, KEY_HOME je selectFirstPartition cmp ah, KEY_RETURN jne inputLoop jmp bootSelectedPartition selectNextPartition: mov ax, [bp + selection] inc ax cmp ax, [listItemCount] jne .done ; At end of list? xor ax, ax ; Then jump to first entry .done: mov [bp + selection], ax jmp mainLoop selectLastPartition: mov ax, [listItemCount] dec ax mov [bp + selection], ax jmp mainLoop selectPreviousPartition: mov ax, [bp + selection] or ax, ax jnz .done ; At top of list? mov ax, [listItemCount] ; Then jump to last entry .done: dec ax mov [bp + selection], ax jmp mainLoop selectFirstPartition: xor ax, ax mov [bp + selection], ax jmp mainLoop ; ======================= Print the OS list ============================ printMenu: mov al, [bp + firstLine] mov [bp + cursorY], al mov si, list ; Start at top of list xor cx, cx ; The index of the current item .loop: lodsb ; String length incl. 0-terminator add al, 3 ; center menu item shr al, 1 ; x = TEXT_COLUMNS / 2 - length / 2 mov dl, TEXT_COLUMNS / 2 sub dl, al mov [bp + cursorX], dl mov al, TRIANGLE_TO_RIGHT call updateMarker inc byte [bp + cursorX] mov di, cx and di, 3 mov bl, [kColorTable + di] ; Text color cmp cx, [bp + selection] jne .print ; Selected item reached? xor bl, BRIGHT_COLOR_MASK ; Highlight it .print: call printstr add si, sizeof(BootLoaderAddress) add byte [bp + cursorX], 1 mov al, TRIANGLE_TO_LEFT call updateMarker inc byte [bp + cursorY] inc cx cmp cx, [listItemCount] jne .loop ret updateMarker: cmp cx, [bp + selection] je .print mov al, ' ' ; Clear marker .print: mov bl, WHITE jmp printChar ; return from subroutine ; ========================== Chainload ========================== bootSelectedPartition: call showCursor call getSelectedBootLoaderAddress lodsb ; Set boot drive mov dl, al mov di, bootSectorDAP+AddressPacket.offset ; Copy start sector mov cx, 4 ; It is stored in a quad word .copy_start_sector: lodsw stosw loop .copy_start_sector mov ah, EXTENDED_READ ; Now read start sector from HD mov si, bootSectorDAP int BIOS_DISK_SERVICES mov si, kReadError jc printAndHalt ; Failed to read sector mov ax, [kMBRSignature] cmp ax, MBR_SIGNATURE mov si, kNoBootablePartitionError jne printAndHalt ; Missing signature CLEAR_SCREEN ; Print "Loading <name>" at top of screen mov word [bp + cursorPosition], 0 mov si, kLoadingMessage mov bl, LIGHT_GRAY call printstr inc byte [bp + cursorX] call getSelectedMenuItem inc si ; Skip string length byte call printstr mov dx, 0x100 xor bh, bh mov ah, SET_CURSOR int BIOS_VIDEO_SERVICES call getSelectedBootLoaderAddress mov dl, [si] ; drive number in dl jmp $$ ; Start loaded boot loader printAndHalt: mov dx, (TEXT_ROWS-4) * 0x100 + (TEXT_COLUMNS / 3) mov [bp + cursorPosition], dx mov bx, 0x0F ; Page number and foreground color call printstr mov ah, READ_CHAR int BIOS_KEYBOARD_SERVICES mov dl, [bp + biosDrive] int BIOS_REBOOT ; Output: ; si address of selected menu item ; Trashes: ; ax, cx getSelectedMenuItem: mov si, list ; Search address of start sector ; of the selected item. mov cx, [bp + selection] inc cx ; Number of required iterations xor ah, ah ; The high-byte of the string length ; see loop body jmp .entry .loop: lodsb ; Length of menu item name add si, ax ; Skip name to BootLoaderAddess add si, sizeof(BootLoaderAddress) .entry: loop .loop ret getSelectedBootLoaderAddress: call getSelectedMenuItem lodsb xor ah, ah add si, ax ; Skip name mov dl, [si] test dl, 0 ; if drive is 0, use boot drive jz .takeOverBootDrive ret .takeOverBootDrive: mov dl, [bp + biosDrive] mov [si], dl ret printStringStage2: PRINT_STRING ; al ... ASCII character ; bl ... color printChar: push ax push bx push cx push dx xor bh, bh ; Write on page 0 mov dx, [bp + cursorPosition] mov ah, SET_CURSOR int BIOS_VIDEO_SERVICES inc byte [bp + cursorX] mov cx, 1 mov ah, WRITE_CHAR int BIOS_VIDEO_SERVICES pop dx pop cx pop bx pop ax ret ; ================================ DATA =========================== bootSectorDAP: istruc AddressPacket at AddressPacket.packet_size, db 0x10 at AddressPacket.block_count, db 0x01 at AddressPacket.buffer, dw 0x0000, 0x07c0 iend kColorTable: db BLUE, RED, GREEN, CYAN kReadError: db 'Error loading sectors', 0x00 kNoBootablePartitionError: db 'Not a bootable partition', 0x00 kLoadingMessage: db 'Loading', 0x00 listItemCount: defaultItem equ listItemCount + 2 timeout equ defaultItem + 2 list equ timeout + 2 ; dw number of entries ; dw the default entry ; dw the timeout (-1 for none) ; entry: ; db size of partition name 0-terminated string ; db 0-terminated string with partition name ; db hard drive number ; quadword start sector %if USE_TEST_MENU dw 0x06 dw 2 dw 5 db 0x06 db 'HAIKU', 0 db 0x80 dw 1, 0, 0, 0 db 0x08 db 'FreeBSD', 0 db 0x80 dw 0x003F, 0, 0, 0 db 0x04 db 'DOS', 0 db 0x80 dw 0x003E, 0, 0, 0 db 0x06 db 'LINUX', 0 db 0x80 dw 0x003F, 0, 0, 0 db 0x08 db 'BeOS R5', 0 db 0x80 dw 0x003F, 0, 0, 0 db 0x07 db 'OpenBSD', 0 db 0x80 dw 0xAAAA, 0, 0, 0 dw kStage1UnusedSpace %endif
